Fig. 5

Assessment of cognitive functions of Dnmt1+/+ and Dnmt1+/− mice at 6 months of age by using the water maze test. Tests and statistical analyses were performed as described in Fig. 2 except that the testing lasted for 8 days, with a reversal of platform position on the last day (day 8) of training. a Improvement of escape latency with the number of trials. No statistically significant differences in the escape latency time were present between the Dnmt1+/+ and Dnmt1+/− mouse groups. However, the latencies of the reversal trials on day 8 were significantly different (p = 0.034) between the groups. The Dnmt1+/− group learned the reversal on day 8 and showed a significant preference for the correct quadrant (p = 0.04), whereas the Dnmt1+/+ mice did not. b Bar graphs illustrating the time that each group spent in one of the four quadrants. Note that both Dnmt1+/+ mice and Dnmt1+/− mice spent significantly more time (p = 0.003) in the correct quadrant during the probe trial on day 7, indicating intact learning and memory functions at the tested age